Medication adherence in combat veterans with traumatic brain injury

Purpose. Medication adherence in combat veterans with traumatic brain injury (TBI) was evaluated. Methods. Patients with a diagnosis of TBI were identified by a computer search of veterans enrolled in the Operation Enduring Freedom/Operation Iraqi Freedom or TBI/polytrauma clinics at Durham Veterans Affairs Medical Center (VAMC) between September 15, 2007, and September 15, 2008. Patients were included if they were at least 18 years old, received medical care and medications at the VAMC for at least 12 continuous months, and were taking at least one maintenance medication. A randomly selected age-matched comparator group without TBI was obtained through a computer-generated convenience sample. A composite adherence score for each patient was calculated using the medication possession ratio (MPR). The most commonly prescribed medications and indicators of increased adherence among the TBI group were also identified. Results. The composite MPR did not significantly differ between groups. The most commonly prescribed medications were selective serotonin-reuptake inhibitors and serotonin-norepinephrine-reuptake inhibitors and other antidepressants; however, these classes were associated with the lowest adherence rates. Factors associated with increased adherence included taking more than five maintenance medications (78%), living with a spouse or significant other (77%), owning a memory-assistance device (74%), and comorbid diagnosis of posttraumatic stress disorder (PTSD) (74%). Conclusion. Medication adherence rates were similar among combat veterans with a diagnosis of TBI and an age-matched comparator group. Factors associated with increased adherence included taking more than five maintenance medications, living with a spouse or significant other, owning a memory-assistance device, and a comorbid diagnosis of PTSD.